Deglycosylation of wogonoside enhances its anticancer potential.

INTRODUCTION: Scutellaria baicalensis is commonly used in Asia as an herbal medicine to treat a variety of ailments, including cancer. Wogonoside, one major constituent of S. baicalensis, can be primarily converted to wogonin through deglycosylation via enteric microbiome metabolism. MATERIALS AND METHODS: The antiproliferative effects of the glycoside (wogonoside) and its deglycosylated compound (wogonin) on a panel of human cancer cell lines from the most common solid tumors were evaluated using the MTS colorimetric assay. Cell cycle and apoptosis were determined using flow cytometry. Enzymatic activities of caspases were measured, and the interactions of wogonin and caspases were explored by a docking analysis. RESULTS: Wogonoside did not have obvious antiproliferative effects on the cancer cells. In contrast, wogonin showed significant antiproliferative activities on all the tested cancer cells. Wogonin arrested the cells in the G1 phase and significantly induced cell apoptosis. The compound also activated the expression of caspases 3 and 9. The docking results suggest that the compound forms hydrogen bonds with Phe250 and Ser251, and π-π interactions with Phe256 in caspase 3, and with Asp228 in caspase 9. CONCLUSIONS: After wogonoside deglycosylation, wogonin significantly enhanced its anticancer potential as a potent anticancer compound derived from S. baicalensis.

Involvement of caspases and their upstream regulators in myocardial apoptosis in a rat model of selenium deficiency-induced dilated cardiomyopathy.

Keshan disease is an endemic dilated cardiomyopathy (DCM) which is closely related with selenium-deficient diet in China. In the previous study, we reported that the low selenium status plays a pivotal role in the myocardial apoptosis in the DCM rats, however, the underlying mechanism remains unclear. The present study aimed to determine whether the intrinsic, extrinsic pathways and the upstream regulators were involved in the myocardial apoptosis of selenium deficiency-induced DCM rats. Therefore, the rat model of endemic DCM was induced by a selenium-deficient diet for 12 weeks. Accompanied with significant dilation and impaired systolic function of left ventricle, an enhanced myocardial apoptosis was detected by TUNEL assay. Western blot analysis showed remarkably increased protein levels of cleaved caspase-3, caspase-8, caspase-9, and cytosolic cytochrome c released from the mitochondria. In addition, the immunoreactivities of p53 and Bax were significantly up-regulated, while the anti-apoptotic Bcl-2 family members Bcl-2 and Bcl-X(L) were down-regulated. Furthermore, appropriate selenium supplement for another 4 weeks could partially reverse all the above changes. In conclusion, the intrinsic, extrinsic pathways and the upstream regulators such as p53, Bax, Bcl-2, and Bcl-X(L )were all involved in selenium deficiency-induced myocardial apoptosis.

Triptolide induces apoptosis in endometrial cancer via a p53­independent mitochondrial pathway.

Triptolide (TP), the primary active component purified from the traditional Chinese herbal medicine Tripterygium wilfordii Hook. F (TWHF), has been shown to possess antitumor activity in several types of solid tumors. In the present study, we investigated the antitumor effect of TP in human endometrial cancer cells (HEC-1B) and elucidated its possible underlying mechanisms. HEC-1B cells were treated with various doses of TP (10, 20, 40, 80, 160 and 320 nM), and the cell viability was assessed by Cell Counting Kit-8 (CCK-8) and flow cytometric analysis. Results indicated that TP inhibited the proliferation of HEC-1B cells in a dose- and time­dependent manner. To further investigate its mechanisms, the levels of apoptosis and the changes in caspase-3/9 expression in HEC-1B cells by pretreatment with z-VAD-fmk, a pan-caspase inhibitor, were detected by CCK-8 and western blotting. The cytotoxic effects of TP were significantly inhibited by z-VAD­fmk. At the molecular level, TP did not effectively activate the p53 signaling pathway, but upregulated caspase-3/9 and downregulated bcl-2 without changing the bax level. Our studies revealed that TP has an effect on the apoptotic ability of endometrial cancer cells via a p53-independent mitochondrial pathway, presenting a novel strategy to evade drug resistance in tumorigenesis. The ability of TP to be a potential chemotherapeutic agent for endometrial cancer should be considered.